[PATCH v2 35/44] x86/dumpstack: remove dump_trace() and related callbacks

From: Josh Poimboeuf
Date: Thu Aug 04 2016 - 18:26:05 EST


All previous users of dump_trace() have been converted to use the new
unwind interfaces, so we can remove it and the related
print_context_stack() and print_context_stack_bp() callback functions.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/include/asm/stacktrace.h | 36 ----------------
arch/x86/kernel/dumpstack.c | 86 ---------------------------------------
arch/x86/kernel/dumpstack_32.c | 35 ----------------
arch/x86/kernel/dumpstack_64.c | 69 -------------------------------
4 files changed, 226 deletions(-)

diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h
index 0a5acde..43a12d6 100644
--- a/arch/x86/include/asm/stacktrace.h
+++ b/arch/x86/include/asm/stacktrace.h
@@ -44,42 +44,6 @@ static inline bool on_stack(struct stack_info *info, void *addr, size_t len)

extern int kstack_depth_to_print;

-struct thread_info;
-struct stacktrace_ops;
-
-typedef unsigned long (*walk_stack_t)(struct task_struct *task,
- unsigned long *stack,
- unsigned long bp,
- const struct stacktrace_ops *ops,
- void *data,
- struct stack_info *info,
- int *graph);
-
-extern unsigned long
-print_context_stack(struct task_struct *task,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data,
- struct stack_info *info, int *graph);
-
-extern unsigned long
-print_context_stack_bp(struct task_struct *task,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data,
- struct stack_info *info, int *graph);
-
-/* Generic stack tracer with callbacks */
-
-struct stacktrace_ops {
- int (*address)(void *data, unsigned long address, int reliable);
- /* On negative return stop dumping */
- int (*stack)(void *data, const char *name);
- walk_stack_t walk_stack;
-};
-
-void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data);
-
#ifdef CONFIG_X86_32
#define STACKSLOTS_PER_LINE 8
#else
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 6a754b9..bdec037 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -56,92 +56,6 @@ void printk_address(unsigned long address)
pr_cont(" [<%p>] %pS\n", (void *)address, (void *)address);
}

-/*
- * x86-64 can have up to three kernel stacks:
- * process stack
- * interrupt stack
- * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
- */
-
-unsigned long
-print_context_stack(struct task_struct *task,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data,
- struct stack_info *info, int *graph)
-{
- struct stack_frame *frame = (struct stack_frame *)bp;
-
- /*
- * If we overflowed the stack into a guard page, jump back to the
- * bottom of the usable stack.
- */
- if ((unsigned long)task_stack_page(task) - (unsigned long)stack <
- PAGE_SIZE)
- stack = (unsigned long *)task_stack_page(task);
-
- while (on_stack(info, stack, sizeof(*stack))) {
- unsigned long addr = *stack;
-
- if (__kernel_text_address(addr)) {
- unsigned long real_addr;
- int reliable = 0;
-
- if ((unsigned long) stack == bp + sizeof(long)) {
- reliable = 1;
- frame = frame->next_frame;
- bp = (unsigned long) frame;
- }
-
- /*
- * When function graph tracing is enabled for a
- * function, its return address on the stack is
- * replaced with the address of an ftrace handler
- * (return_to_handler). In that case, before printing
- * the "real" address, we want to print the handler
- * address as an "unreliable" hint that function graph
- * tracing was involved.
- */
- real_addr = ftrace_graph_ret_addr(task, graph, addr,
- stack);
- if (real_addr != addr)
- ops->address(data, addr, 0);
-
- ops->address(data, real_addr, reliable);
- }
- stack++;
- }
- return bp;
-}
-EXPORT_SYMBOL_GPL(print_context_stack);
-
-unsigned long
-print_context_stack_bp(struct task_struct *task,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data,
- struct stack_info *info, int *graph)
-{
- struct stack_frame *frame = (struct stack_frame *)bp;
- unsigned long *retp = &frame->return_address;
-
- while (on_stack(info, stack, sizeof(*stack) * 2)) {
- unsigned long addr = *retp;
- unsigned long real_addr;
-
- if (!__kernel_text_address(addr))
- break;
-
- real_addr = ftrace_graph_ret_addr(task, graph, addr, retp);
- if (ops->address(data, real_addr, 1))
- break;
-
- frame = frame->next_frame;
- retp = &frame->return_address;
- }
-
- return (unsigned long)frame;
-}
-EXPORT_SYMBOL_GPL(print_context_stack_bp);
-
void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
unsigned long *stack, char *log_lvl)
{
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 922b722..53d939e 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -113,41 +113,6 @@ unknown:
return -EINVAL;
}

-void dump_trace(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data)
-{
- unsigned long visit_mask = 0;
- int graph = 0;
-
- task = task ? : current;
- stack = stack ? : get_stack_pointer(task, regs);
- bp = bp ? : (unsigned long)get_frame_pointer(task, regs);
-
- for (;;) {
- const char *begin_str, *end_str;
- struct stack_info info;
-
- if (get_stack_info(stack, task, &info, &visit_mask))
- break;
-
- stack_type_str(info.type, &begin_str, &end_str);
-
- if (begin_str && ops->stack(data, begin_str) < 0)
- break;
-
- bp = ops->walk_stack(task, stack, bp, ops, data, &info, &graph);
-
- if (end_str && ops->stack(data, end_str) < 0)
- break;
-
- stack = info.next_sp;
-
- touch_nmi_watchdog();
- }
-}
-EXPORT_SYMBOL(dump_trace);
-
void
show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
unsigned long *sp, char *log_lvl)
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 55ee1f3..9f7a9f9 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -137,75 +137,6 @@ unknown:
return -EINVAL;
}

-/*
- * x86-64 can have up to three kernel stacks:
- * process stack
- * interrupt stack
- * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
- */
-
-void dump_trace(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data)
-{
- unsigned long visit_mask = 0;
- struct stack_info info;
- int graph = 0;
- int done = 0;
-
- task = task ? : current;
- stack = stack ? : get_stack_pointer(task, regs);
- bp = bp ? : (unsigned long)get_frame_pointer(task, regs);
-
- /*
- * Print function call entries in all stacks, starting at the
- * current stack address. If the stacks consist of nested
- * exceptions
- */
- while (!done) {
- const char *begin_str, *end_str;
-
- get_stack_info(stack, task, &info, &visit_mask);
-
- /* Default finish unless specified to continue */
- done = 1;
-
- switch (info.type) {
-
- /* Break out early if we are on the thread stack */
- case STACK_TYPE_TASK:
- break;
-
- case STACK_TYPE_IRQ:
- case STACK_TYPE_EXCEPTION ... STACK_TYPE_EXCEPTION_LAST:
-
- stack_type_str(info.type, &begin_str, &end_str);
-
- if (ops->stack(data, begin_str) < 0)
- break;
-
- bp = ops->walk_stack(task, stack, bp, ops,
- data, &info, &graph);
-
- ops->stack(data, end_str);
-
- stack = info.next_sp;
- done = 0;
- break;
-
- default:
- ops->stack(data, "UNK");
- break;
- }
- }
-
- /*
- * This handles the process stack:
- */
- bp = ops->walk_stack(task, stack, bp, ops, data, &info, &graph);
-}
-EXPORT_SYMBOL(dump_trace);
-
void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
unsigned long *sp, char *log_lvl)
{
--
2.7.4